An experimental animal head injury model productive of graded and prolonged coma is being developed. Drugs are being evaluated and tested in the head injury model for their effect in altering prolonged coma. Parallel experiments are to be conducted on the mechanism of development of astroglial swelling. Drugs to be evaluated in the in vivo animal head injury model are initially tested to determine effectiveness in inhibiting glial swelling in vitro. Companion studies on the changes in catecholamine levels and turnover in the head injured animal brain and spinal cord are planned together with studies of the electrospinogram in the spinal cord injured animal.